Heel lift for boots or shoes



Dec. 24, 1929.

C. RQBERTS HEEL LIFT FOR BOOTS OR SHOES Filed April 2'7. 192'? wees Patented Dec. 24, 1929- NI E STATES PATENT oFncE cLIEroRn ROBERTS, F wiNoHESrEfi, MASSACHUSETTS, ASSIGNOR, BY MESNE As- SIGNMENTS, '10 UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY HEEL 1.1m FOR BOOTS 0 SHOES Application filed April 27,

The present invention relates to heel lifts for boots or Shoes, and more particularly to a heel lift of rubber compound, or similar or equivalent material, adapted for attachment to the lower portion of a shoe heel base and serving as the tread portion thereof.

This application is ,a continuation in part of the application of Cliflord Roberts, Serial No. 36,614, filed June 12, 1925.

Heels of this character, generally known-as half heels or toplifts, have long been used to replace the usual heel lifts and provide a cushion forthe heel of the wearer. These heels are commonly provided with nail-retaining washers embedded in the rubber body and designed to secure the heel upon the adj acent base. In order to provide a tight, close joint between the rubber toplift and theadoining heel base, heels of this type were first providedwith a sealing rand about the margin intended to secure a close joint through compression of the marginal portion of the heel upon application tothe base. Subsequently the heels were made with a pronounced concavo-con'vex form,or as the section of a hollow sphere, so that the distortion of the heel, in application, from the natural curved form to a flat form would maintain a tight edge by virtue of the natural resiliency of the. heel. In the first form of heel, the nailretaining washers are spaced in close proximity to the margin in order to secure the desired tight'edge, andin the second form of heel the washers are grouped within the cen-' f ortoplift, w

" heel base to provide a tight edge and a secure tral area where the lateral spreading upon the application of the heel is least pronounced. In bothtypes of heels the fastening nails must be driven at the points circumscribed by the washers. Due to the difiiculty of properlylocating and inserting the attaching nails with the heel-attaching machinery used in shoe factories, the concavoconvex form of 'heel has been ractically limited in its use' to application y cobblers or shoe repairers. It has lon been recognized that a half heel iich could be applied to the shoe I attachment withoutan accurate and. precise location of'the attaching' nails, would re- .sult-in-niany desirable advantages from the operation,

the core could not be successfully bonded Within the body of rubber compound or did not offer a satisfactory medium for holding the attaching nails. In addition, certain of these prior suggestions could not have been successfully employed in connection with half heels or tread lifts, due to the premature exposure of the core and resultant blistering and loosening of the heel after a short period of wear.

I have determined that a very satisfactory type. of half heel provided with an embedded core may be produced by the employment of a core having a substantially flat upper or attaching face and an under face shaped in a manner to provide a gradual increase in thickness of the core from the edge portion toward the central portion. This type of core is of sufficient thickness to resist distortion strains incident to the vulcanizing and may be permanently bonded within the surrounding body of rubber in a manner to provide an ideal nailing medium for the rubber half heel without interference with the normal and usual function of the heel duringwwear. The under surface of the core is preferably Shaped in such a manner that the core in section corresponds generally to the average residuum of that portion of the half heel subjected to the greatest wear, or in other words, the under surface 'of the core, which is generall convex from the central portion toward t e thin marginal portions at the sides and rear, is, generally speakmg, equidistant from all points of the worn tread surface throughout the afea of greatest wear. This results in a completed toplift or heel which may be worn entirely down to'the portion extending about the sides and rear and having an angle of bevel with the plane of the core as a whole which may preferably be less than 35. The tread'face of the finished heel is preferably provided with some 5 form of embossing which determines" a nail-- ing area generally coincident with this tapered marginal portion. This embossing may take the form of individual nailing areas or a D-shaped grid. When such a core is embedded in the upper portion of a heel body of rubber compound, it has several distinct and important advantages. The core is preferably constructed of a pluralit of thin plies of wood with the grain crosse to make a rigid and non-deformable core, which at the same time is readily penetrable by attaching nails. This core is so located in the heel body that the upper flat face of the'co're abuts the adjoining face ofthe heel, and forms in conjunction therewith a rigid and inextensible base for the yielding body of the heel tread. In the present-form of the invention the heel body is provided with a sealing randsloping upwardly from the marginal portion of 26 the core to the outer edge of the heel. This sealing rand projects inwardly over the upper flat face of the core in a manner toprovide a locking fin and augment the bondingof the core within the surrounding body of flexible material. In attaching a heel or tread member of this character, the sealing flange is flattened and distorted substantially into the plane of the upper face of the core, the compression of the heel body at the marginal portion resulting in a tight, close joint with the heel base. It will be evident to those skilled in the art that in the usual practice of molding,

the core is placed upon the bottom of the mold' in an inverted position, a rubber biscuit superimposed thereover, and the whole subjected to vulcanizing heat and pressure. In order to form the locking fin about the margin of the core, the latter is supported throughout its major central area only, leaving the marginal edge about the sides and rear free and unsupported. If the pressure upon the inverted core is confined substantially to that portion of the core supported by the bottom of the mold, there is no tendency prior to or during the vulcanizing operation to undulystrain or distort the core into conformity with the supporting face of the mold. With the present construction, the shape of the core is such that the pressure to which the core is sub- 5 jected gradually decreases as the free marginal edge of the core is approached. This desirable result is accomplished by causing the upper portion of the inverted core to recede from the opposite portion of the mold face as the outer edge of the core is approached, thus providing a space betweenthe upper face of the inverted core and the upper face of the mold which gradually increases in depth or thickness toward the marginal portion of-the core. It has been "found in actual practice'- -corresponding to the slope of wear upon t e that with this colistruction a core sufliciently thin to adapt it for embodiment in a half heel has the requisite strength and rigidity to undergo the vulcanizing operation without distortion.

The provision of a gradual and relatively wide tapered portion upon the under face of the core permits the desired advantages to be secured without interfering with the attachment of the heel by a possible diversion of the attaching nails, which is not unusual when employing embedded washers or similar ex pedients.

Referring to the accompanying drawings,

Fig. 1 represents atop plan view of a heel embodying the features of the invention;

Fig. 2 is a sectional elevation upon the line 22 of Fig. 1;

Fig. 3 is a section upon. the line 3-3 of Fig. 1; and

Fig. 4 is a bottom plan view of the heel.

The heel, as shown in the illustrated embodiment of the invention, comprises a nailholding core 10 consisting of three plies,'indicated respectively at 11, 12 and 13. This core is provided with a generally heel-shaped contour and occupies the major portion of the area within the heel body. Surrounding the core is a heel body 14 of rubber compound, which is molded about the core in the usual '95 vulcanizing operation and which may have any desired character of surface ornamentation or embossing thereon. In the present invention, the tread face of the heel body is provided with a series of raised bosses 16, each intended to circumscribe a nailing area. The attaching portion of the heel body is provided with a sealing rand or flange 18 which is formed bya surface 20 curving upwardly from the junction of the heel body at the margin of the core. As indicated more particu larly in Figs. 1 to 3, inclusive, the material of the heel body projects inwardly over the core in a manner to form a locking flange 22. By the attachment of the heel lift to a suitable base, the sealing rand is flattened out and thecore abuts the adjacent surface of the base. This construction insures the retention of a permanently tight edge, due not only to the compression of the marginal portion of the heel body but the permanent locking of the core within the heel body and the insurance against loosening of the heel body from the core under the severe pounding incident to the wear of the heel. The under face of the core is substantiallyconvex, tapering from the central portion toward the sides and rear toprovide athin, reduced margin. As indi- *cated more particularly in Figs. 2 and 3, the

slope of the underface corresponds essentially 25 der face of the core to provide a gradual ta er heel and insufficient to divert or otherwise interfere with the insertion of the attaching nails. As indicated more particularly, the portion of greatest wear upon the heel is indicated generally by dot and dash lines in Figs. 2 and 3, this wearing area extending over the outer side and rear portions of the heel body and conforming in general to the slope of the tapered edge of the core underlying it. In addition to the advantages hereinbefore enumerated for this type of core, the beveling or tapering of the under face promotes the permanent bond between the core and heel body, due to the fact that the tapered or convex under surface avoids the formation of sharp corners or edges at the sides and rear of the core which are directly subjected to a severe pounding and cutting action in a period of normal wear. With the core not so formed or constructed, this pounding action sooner or later results in a progressive loosening of the heel body and a corresponding shortening of its life.

What is claimed is: p

1. A half heel for boots or shoes comprising a body portion of resilient, vulcanized material capable of being distorted to a substantially fiat form in attaching to a heel base, and anembedded and non-deformable core of nail-penetrable material having a flat attaching face adapted to abut directly against the heel base and form the attaching face of the heel and a substantially convex under face terminating in a' reduced edge at the sides and rear of the core.

2. A half heel for boots and shoes compris-' ing a body portion of resilient, vulcanized material capable of being distorted to fiat form in attachingv to the heel base, a core of nailpenetrable material embedded in the portion of the body and having a fiat, upper face adapted to abut directly against the heel seat and form the attaching face of the heel, and a comparatively wide and gradually tapered portion extending about the rear and side margin of the coreat the under face,

and a nailing area upon the tread face of the body substantially coincident with the tapered portion of the core through which attaching nails are intended to be inserted.

3. A half heel for boots and shoes comprising a body portion of resilient, vulcanized material, a core of nail-holdin material embedded in the upper portion of the body and having a flat attaching face adapted to abut directly against the heel seat, and an under beveled portion extending about the sides and rear of the core and a portiorr of the heel body overlying the core at the margin 'of the attaching face to assist in looking the core therein.

4. A half heel for boots and shoes comprising a body portion of resilient, vulcanized material havin material having a upper a depth or thickness approxiheel, a flat, non-deformable core of nail-pene- 5. A half heel for boots and shoes comprising a heel body of resilient, vulcanized material having a marginal sealing flange extending about the attaching face, and a nondeformable core of nail-penetrable material embedded in'the upper portion of the body and having a flat attaching face which abuts directly against a heel seat during attach-- ment, the marginal portion of the attaching face of the heel body extending over the upper face of the core and adapted to be flattened during attaching to provide a substantially flat attaching face throughout the entire area of the heel.

6. A half heel for boots or shoes comprising a body portion of resilient, vulcanized material, a substantially non-deformable heel-shaped core having a flat attaching face exposed over substantially its entire area with an integral locking fin extending inwardly thereon from the body, and a tapered under margin at the sides and rear not less in width than the locking fin.

7. A half heel for boots or shoes comprising a body portion of resilient, vulcanized generally cupped attaching face, a heel-shaped core embedded therein and havin a flat exposed upper face forming the centrad part of the attaching face, and an under face receding toward the side and rear edges from the opposing portions ofthe tread surface of the heel.

. 8. A core for rubber half heels consisting of 'nail-holdin material substantially nondeformable un er the strains of the vulcanizing operation, and having a flat upper portion adapted to form the attaching face of the heel when the core is embedded therein,- and an under portion tapering from the central area to a relatively thin edge at the sides and rear of the core.- I

CLIFFORD ROBERTS.

mating one-ha f the thickness of theshoe 

